diff options
| -rw-r--r-- | include/linux/skbuff.h | 91 | ||||
| -rw-r--r-- | net/core/dev.c | 32 | ||||
| -rw-r--r-- | net/core/skbuff.c | 41 |
3 files changed, 161 insertions, 3 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h index 92470084458..f96bc91bf0a 100644 --- a/include/linux/skbuff.h +++ b/include/linux/skbuff.h @@ -132,6 +132,57 @@ struct skb_frag_struct { __u32 size; }; +#define HAVE_HW_TIME_STAMP + +/** + * skb_shared_hwtstamps - hardware time stamps + * + * @hwtstamp: hardware time stamp transformed into duration + * since arbitrary point in time + * @syststamp: hwtstamp transformed to system time base + * + * Software time stamps generated by ktime_get_real() are stored in + * skb->tstamp. The relation between the different kinds of time + * stamps is as follows: + * + * syststamp and tstamp can be compared against each other in + * arbitrary combinations. The accuracy of a + * syststamp/tstamp/"syststamp from other device" comparison is + * limited by the accuracy of the transformation into system time + * base. This depends on the device driver and its underlying + * hardware. + * + * hwtstamps can only be compared against other hwtstamps from + * the same device. + * + * This structure is attached to packets as part of the + * &skb_shared_info. Use skb_hwtstamps() to get a pointer. + */ +struct skb_shared_hwtstamps { + ktime_t hwtstamp; + ktime_t syststamp; +}; + +/** + * skb_shared_tx - instructions for time stamping of outgoing packets + * + * @hardware: generate hardware time stamp + * @software: generate software time stamp + * @in_progress: device driver is going to provide + * hardware time stamp + * + * These flags are attached to packets as part of the + * &skb_shared_info. Use skb_tx() to get a pointer. + */ +union skb_shared_tx { + struct { + __u8 hardware:1, + software:1, + in_progress:1; + }; + __u8 flags; +}; + /* This data is invariant across clones and lives at * the end of the header data, ie. at skb->end. */ @@ -143,10 +194,12 @@ struct skb_shared_info { unsigned short gso_segs; unsigned short gso_type; __be32 ip6_frag_id; + union skb_shared_tx tx_flags; #ifdef CONFIG_HAS_DMA unsigned int num_dma_maps; #endif struct sk_buff *frag_list; + struct skb_shared_hwtstamps hwtstamps; skb_frag_t frags[MAX_SKB_FRAGS]; #ifdef CONFIG_HAS_DMA dma_addr_t dma_maps[MAX_SKB_FRAGS + 1]; @@ -465,6 +518,16 @@ static inline unsigned char *skb_end_pointer(const struct sk_buff *skb) /* Internal */ #define skb_shinfo(SKB) ((struct skb_shared_info *)(skb_end_pointer(SKB))) +static inline struct skb_shared_hwtstamps *skb_hwtstamps(struct sk_buff *skb) +{ + return &skb_shinfo(skb)->hwtstamps; +} + +static inline union skb_shared_tx *skb_tx(struct sk_buff *skb) +{ + return &skb_shinfo(skb)->tx_flags; +} + /** * skb_queue_empty - check if a queue is empty * @list: queue head @@ -1730,6 +1793,11 @@ static inline void skb_copy_to_linear_data_offset(struct sk_buff *skb, extern void skb_init(void); +static inline ktime_t skb_get_ktime(const struct sk_buff *skb) +{ + return skb->tstamp; +} + /** * skb_get_timestamp - get timestamp from a skb * @skb: skb to get stamp from @@ -1739,11 +1807,18 @@ extern void skb_init(void); * This function converts the offset back to a struct timeval and stores * it in stamp. */ -static inline void skb_get_timestamp(const struct sk_buff *skb, struct timeval *stamp) +static inline void skb_get_timestamp(const struct sk_buff *skb, + struct timeval *stamp) { *stamp = ktime_to_timeval(skb->tstamp); } +static inline void skb_get_timestampns(const struct sk_buff *skb, + struct timespec *stamp) +{ + *stamp = ktime_to_timespec(skb->tstamp); +} + static inline void __net_timestamp(struct sk_buff *skb) { skb->tstamp = ktime_get_real(); @@ -1759,6 +1834,20 @@ static inline ktime_t net_invalid_timestamp(void) return ktime_set(0, 0); } +/** + * skb_tstamp_tx - queue clone of skb with send time stamps + * @orig_skb: the original outgoing packet + * @hwtstamps: hardware time stamps, may be NULL if not available + * + * If the skb has a socket associated, then this function clones the + * skb (thus sharing the actual data and optional structures), stores + * the optional hardware time stamping information (if non NULL) or + * generates a software time stamp (otherwise), then queues the clone + * to the error queue of the socket. Errors are silently ignored. + */ +extern void skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps); + extern __sum16 __skb_checksum_complete_head(struct sk_buff *skb, int len); extern __sum16 __skb_checksum_complete(struct sk_buff *skb); diff --git a/net/core/dev.c b/net/core/dev.c index 1e27a67df24..d20c28e839d 100644 --- a/net/core/dev.c +++ b/net/core/dev.c @@ -1672,10 +1672,21 @@ static int dev_gso_segment(struct sk_buff *skb) return 0; } +static void tstamp_tx(struct sk_buff *skb) +{ + union skb_shared_tx *shtx = + skb_tx(skb); + if (unlikely(shtx->software && + !shtx->in_progress)) { + skb_tstamp_tx(skb, NULL); + } +} + int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, struct netdev_queue *txq) { const struct net_device_ops *ops = dev->netdev_ops; + int rc; prefetch(&dev->netdev_ops->ndo_start_xmit); if (likely(!skb->next)) { @@ -1689,13 +1700,29 @@ int dev_hard_start_xmit(struct sk_buff *skb, struct net_device *dev, goto gso; } - return ops->ndo_start_xmit(skb, dev); + rc = ops->ndo_start_xmit(skb, dev); + /* + * TODO: if skb_orphan() was called by + * dev->hard_start_xmit() (for example, the unmodified + * igb driver does that; bnx2 doesn't), then + * skb_tx_software_timestamp() will be unable to send + * back the time stamp. + * + * How can this be prevented? Always create another + * reference to the socket before calling + * dev->hard_start_xmit()? Prevent that skb_orphan() + * does anything in dev->hard_start_xmit() by clearing + * the skb destructor before the call and restoring it + * afterwards, then doing the skb_orphan() ourselves? + */ + if (likely(!rc)) + tstamp_tx(skb); + return rc; } gso: do { struct sk_buff *nskb = skb->next; - int rc; skb->next = nskb->next; nskb->next = NULL; @@ -1705,6 +1732,7 @@ gso: skb->next = nskb; return rc; } + tstamp_tx(skb); if (unlikely(netif_tx_queue_stopped(txq) && skb->next)) return NETDEV_TX_BUSY; } while (skb->next); diff --git a/net/core/skbuff.c b/net/core/skbuff.c index ab7d2e9f02f..e5a8351ff12 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -55,6 +55,7 @@ #include <linux/rtnetlink.h> #include <linux/init.h> #include <linux/scatterlist.h> +#include <linux/errqueue.h> #include <net/protocol.h> #include <net/dst.h> @@ -215,7 +216,9 @@ struct sk_buff *__alloc_skb(unsigned int size, gfp_t gfp_mask, shinfo->gso_segs = 0; shinfo->gso_type = 0; shinfo->ip6_frag_id = 0; + shinfo->tx_flags.flags = 0; shinfo->frag_list = NULL; + memset(&shinfo->hwtstamps, 0, sizeof(shinfo->hwtstamps)); if (fclone) { struct sk_buff *child = skb + 1; @@ -2945,6 +2948,44 @@ int skb_cow_data(struct sk_buff *skb, int tailbits, struct sk_buff **trailer) } EXPORT_SYMBOL_GPL(skb_cow_data); +void skb_tstamp_tx(struct sk_buff *orig_skb, + struct skb_shared_hwtstamps *hwtstamps) +{ + struct sock *sk = orig_skb->sk; + struct sock_exterr_skb *serr; + struct sk_buff *skb; + int err; + + if (!sk) + return; + + skb = skb_clone(orig_skb, GFP_ATOMIC); + if (!skb) + return; + + if (hwtstamps) { + *skb_hwtstamps(skb) = + *hwtstamps; + } else { + /* + * no hardware time stamps available, + * so keep the skb_shared_tx and only + * store software time stamp + */ + skb->tstamp = ktime_get_real(); + } + + serr = SKB_EXT_ERR(skb); + memset(serr, 0, sizeof(*serr)); + serr->ee.ee_errno = ENOMSG; + serr->ee.ee_origin = SO_EE_ORIGIN_TIMESTAMPING; + err = sock_queue_err_skb(sk, skb); + if (err) + kfree_skb(skb); +} +EXPORT_SYMBOL_GPL(skb_tstamp_tx); + + /** * skb_partial_csum_set - set up and verify partial csum values for packet * @skb: the skb to set |